Logical vs. Physical attribute numbering

We had a discussion a few days ago about removing attribute padding from
disk storage structures to fit more information on the disk.

Now, I question whether it is worth the added complexity to do this, but
the idea of having different logical and physical numbering of columns
seems like it may solve several problems:

o Columns can be reordered to minimize padding
o We can move variable length columns to the end, improving
performance
o We can fix inheritance problems in ADD COLUMN
o We can implement fast DROP COLUMN by renumbering the column
out of visibility

Comments?

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
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